Centrifugal pump.



UNITED STATES PATENT OFFICE.

ROBERT WV. CHRISTIAN, OF BANNAOK, MONTANA.

CENTRIFUGAL PUMP.

SPEGIFICATON forming'- part of Letters Patent No. 678,223, dated July 9, 1901.

Application iiled September 6, 1900.l Serial No. 295.218. (No medal.)

To all who-m, it' may concern.-

Beit known that I, ROBERT W. CERIsTiAN, a citizen of the United States, residing at Bannack, in the county of Beaverhead and State of Montana, have invented a new and useful CentrifugalPump, of which the following is a specification.

This invention relates to improvements in centrifugal pumps, and has for one object to produce a pump of this character provided with means for causing Water under p ressure to flow between the opposed surfaces of the casings and runner and to prevent sand or other gritty substances from working between such faces, and thereby producing undue friction, which not only decreases the effectivenessA of the pump, but produces undue wear upon the bearing-surfaces.

A further object of the invention is to provide the interior faces of the pump-casing exposed to the wear of the gritty substances handled with linings made up of removable and interchangeable sections.

A still further object of the invention is to provide the interior surfaces of the runner with lining-sections and to guard the vanes or blades by providing them with removable and interchangeable wear-plates, which not only cover the working surfaces of said vanes or blades, but project beyond them at the delivery end of the runner-throat to constitute wear-points.

A still further object of the invention is to provide a water seal intermediate of the bearing and pump for the protection of the latter; and other and subordinate objects will hereinafter more fully appear as the necessity for their accomplishment is developed in the succeeding description, when taken in connection with the accompanying drawings, serving to illustrate the preferred embodiment of the invention.

In said drawings, Figure 1 is a sectional elevation of the pump and its mountings and connections. Fig. 2 is a sectional View through the pump-casing in a plane at right angles to Fig. 1, showing the runner in elevation and a portion of the throat broken away to disclose interior parts shown partly in section; and Fig. 3 is a sectional view on the line 3 3 of Fig. 2.

Referring to the numerals of reference employed to designate corresponding parts in the several views, 1 indicates a substantially circular pump-casing comprising front and rear circular walls 2 and 3, formed at their peripheries with annular flanges 4 of angular form for the connection of an annular rim-casing 5, which, as will be seen hereinafter, forms an annular delivery-chamber 6, communicating with the delivery-pipe 7 through a port 8, the pipe 7 being arranged, as usual, in a direction tangentially to the pump casing, as more clearly shown in Fig. 2 of the drawings. The front Wall 2 of the casing is provided with a concentric annular extension 9, defining what may be termed the suction-head of the pump, from the front of which latter extends a coaxial pipe connection 10, to which is bolted or otherwise secured the contiguous end of the supply-pipe 11, through which the material to be pumped is drawn into the casing by the rotary runner or impeller 12, mounted upon one end of the pumpshaft 13, journaled in suitable bearings 14: and provided with a belt-pulley 15 or other power-transmitting devices for the transmission of rotary motion to the shaft for the purpose of causing the runner to revolve in the v pump-casing. The runner is composed of parallel annular Walls 16 17, the rear wall 17 being formed with an inwardly-extending hub 18, terminating nearly in the plane of the wal116 and extendedby a conical nose 19, screwed upon the reduced end of the shaft 13 and located Within the trunco-conical throat 20 of the runner. This throat 2O is sprung from the wall 16 and is coaxial with the shaft to form an annular passage into the runner from the suction-pipe l1. This annular passage is obviously formed between the opposed inclined annular faces of the nose and throat. Within the runner are formed a series of radially-disposed longitudinally-curved vanes runner and through the delivery-pipe 7 for iinal delivery.

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It will be noted that the sand or other gritty material seeking access to the runner proper from the throat will tend to grind away those portions of the vane edges which are exposed before the delivery end of the throat. To overcome this wear, or rather to provide for the ready renewal of the worn faces, I cut away the lower end of each vane at one side thereof, as indicated at 22, and on the active face of each vane I mount a detachable wearplate 23, which is interchangeable with other wear-plates mounted on the other vanes and which is provided with a thickened wearpoint 2t, which sets within the cut-away portion of the blade and is presented edgewise across the delivery end of the throat. These wear or guard plates are preferably made of very hard metal-as, for instance, manganese steel. In addition tothe provision of the plates 23, which form the working surfaces of the vanes and receive the impact of the gritty material as it passes into the runner from the throat, I provide the walls 16 and 17 with lining-plates 25 and 26. These plates are bolted to the walls of the runner, and the plates 2G have one side edge 27 opposed to the face ofthe adjacent wear-plate 23 to assist in the retention thereof and one end edge 28 presented to the rear face of another vane. The plates 25 are likewise employed to aid in the retention of the wear-plates 23; but they are not necessarily extended entirely to the next adjacent vane, inasmuch as these several lining-plates are disposed longitudinally in the general direction of the vanes and as the throat of the runner interrupts the inner ends of the plates 25. In like manner the inner face of the trunco-conical throat 2O is covered by a sectional lining 29, and the rim-casing 5 is protected by an annular lining 30, retained in place by annular plates 3l, bolted to the casing 5 and constituting continuations of the lining 30.

My invention as thus far described comprehends the equipment of the centrifugal pump with detachable and interchangeable wear and lining plates covering the various working surfaces, which are liable to be worn by constant contact with violently-agitated sand and grit and having its vanes provided with wear-points projecting beyond the edges thereof and receiving the impact of material delivered to the runner from the throat. This construction effectually provides for the protection of the interior surfaces of the pump; but I have found in practice that the eective operation of pumps of this character is greatly decreased by the deposit of grit between the opposed faces of the runner and casing. I have also found that it is practically impossible to secure such joints between the casing and runner as will permit the latter to rotate easily and at the same time be closed against the ingress of the frictional substances referred to. It has therefore appeared that provision other than a mere nicety of construction must be provided for the accomplishment of the desired end. I have therefore devised a novel construction by means of which I secure a constant circulation of water between the opposed faces of the fixed and movable parts, the circulation being directed in opposition to the direction of movement which the grit would be required to take in order to gain access to the space between the working parts. In other words, I provide not merely a water lubricant under pressure, but I produce a movement or. flow between the bearing-surfaces by providing a water or other liquid packing suitably introduced between the faces and subjected to pressure, which tends to force it to the interior of the pump through those spaces exposed to the gritty material, for the conveyance of which the pump is employed. It is obvious, therefore, that any tendency of the grit to pass through exposed openings will be offset by the counteriow of the water packing.

In Fig. l of the drawings I have clearly illustrated the construction which I have devised for carrying the above theory into practice. This construction comprehends the employment of a gland located within the suctionhead 9 and comprising a thimble 32, extending into the pipe connection lO from the inner edge of an annular follower 33, from the inner face of which extends a transverselyinclined annular flange 34, which constitutes the gland proper, as its inclination is such as to make it conform substantially to the inclination of the truneo-conical throat 20. As shown in the drawings, the flange 34 springs from the follower 33 at a point removed from the periphery of the latter, the purpose ot' this beingto define an annular supply chamber or reservoir 35, surrounding the gland within the suction-head and placed in communication with the space between the flange 34 and throat 2O by a series of openings 36, piercing the flange 3i, preferably at a point adjacent to the follower 33, in order that Water forced through these openings from the reservoir 35 will be projected directly between the end face of the throat 20 and the contiguous face of the follower 33. This direct projection of the water at this point is desirable, for the reason that it is here the gritty particles are most liable to find access to the interval between the bearing-surfaces. Water under pressure is supplied to the reservoir 35 through a water-supply pipe 37, piercing the wall of the suction-head 9 and designed to force the water into the chamber 35, thence through the openings 36 to the space intermediate of the throat 20 and gland 34, between which faces the water circulates and escapes through the annular opening 38, defined between the end face of the throat and the opposed face of the follower, and the annular opening 39, defined between the periphery of the wall 16 and the adjacent portion of the pump-casing.

It will be understood that the wall 16 is located a suitable distance from the wall 2 of ICO IIO

the pump-casing to provide a suitable intervening space in communication with the space between the gland and throat to provide for the circulation f the water packing. Obviously the pressure of the water packing and its quantity must be regulated in accordance with the character of the material being pumped, and for this reason I have mounted the gland adjustably, this adjustment being obtained by means of adjustmentscrews 40, passed through the front wall of the suction-head 9 and bearing against the follower. Through the adjustment of these screws the gland may be moved toward or from the throat for the purpose of regulating the dimensions of the packing-chamber 41, and thereby controlling the ow of the packing and the force with which the latter is projected through the openings 38 and 39. An expedient somewhat similar to that described is resorted to for the purpose of protecting the bearing 14 from gritty particles which might work their way through the casing at the point where the shaft enters. The rear side of the casing-that is to say, the wall 3 thereof-is provided with a stuffing-box 42, provided wit-h an internal annular waterchamber 43, into which water under pressure is supplied through a comparatively small pipe 44.

The operation of my pump is as follows: The shaft 13 is rotated by the application of power in anysuitable manner, and the runner or impeller is revolved at a high rate of speed. The result of this will be to cause water and sand or other substance to be drawn from the pipe 1l and into the throat 20, whence it is delivered to the spaces intermediate of the vanes of the runner and is discharged by centrifugal force into the annular' deliverychamber 6, and thence through the deliverypipe 7. The various interior faces of the pump will be protected by the hard-metal wear-plates and sectional linings described, and the water packing forced into the packing-chamber from the annular reservoir 35 will be discharged through those openings between the wear-faces exposed to the gritty particles. If the material handled is very fine, the gland may be advanced toward the throat to constrict the packing-chamber and the openings therefrom for the dual purpose of reducing the openings and securing a more powerful projection of the water to the interior of the pump through the openings 38 and 39.

From the foregoing it will be observed that I have produced a simple, durable, and effective centrifugal pump embodying a construction calculated to effect the accomplishment of the various objects stated; but while the present embodiment of my invention appears at this time to be preferable I wish to be distinctly understood as reserving the right to effect any and all modifications of both the construction and arrangement of the device which may be suggested by experience and experiment, provided that such variations from the construction shown are embraced clearly-within the spirit of the invention.

1. The combination with a pair of relatively movableinterfitting members defining an intermediate packing-chamber open at both ends and wholly unobstructed, of means for supplying a fluid under pressure to the packing-chamber at a point intermediate of its ends to compel the fluid to circulate within the chamber and to escape into the casing and suction-head respectively from the opposite endsof said chamber. Y

, 2. In a pump, the combination with a casing, of a runner rotatable therein and having an annular bearing-surface opposed to butV wholly out of contact with the casing to define an intermediate packing-chamber opening into the suction-head and casing at the inner and outer edges of the annular bearingsurface, and meansfor supplying fluid under pressure to the packing-chamber to compel said fluid to ow between the bearingfaces and to escape into the suction-head and casing from the opposite ends of the chamber.

3. In a pump, the combination with a casing, and' a suction-head extending therefrom, of a rotary runner mounted within the casing and provided with a throat ext-ended into the suction-head, and means for directing a circulation of fluid over the exterior surface of the throat and the adjacent surface of the runner and into the suction-head and casing around the outer edges of said surfaces whereby a single source of water-supply sufces to cause an iniiow of water within both the head and casing.

4. In a pump, the combination with a casing, a rotary runner therein provided with a laterally-extending throat, `a hollow gland member receiving therein the throat of the runner, and means for supplying fluid under pressure to the interval between the throat and gland member to induce a circulation between the opposed surfaces of said elements and into the casing between the gland member and the opposed edge of the throat.

5. In a pump, the combination with a casing and a rotary runner therein provided with a laterally-extending throat, of an adjustable hollow gland member mounted within the casing, said gland member encircling the throat and having one wall opposed to the end thereof, and means for supplying fluid underV pressure to the packing-chamber defined between the throat and gland member to compel the circulation of said Huid within the chamber and its passage into the casing around the end of the throat.

6. In a pump, the combination with a casing provided with a suction-head, of a rotary runner within the casing provided with a trunco-conical throat, an adjustable gland located within the suction-head, said gland IOO IIO

encircling the throat and formed with an annular water-chamber in communication with the packing-chamber defined between the opposed faces of the throat and gland, and means for supplying fluid under pressure to the annular chamber of the gland.

'7. In a pump, the combination with a casing having a suction-head extended therefrom, of a gland member located within the suction-head and comprising an annular follower, and an annular inclined gland-flange provided with openings, means for supplying water to the interior of the suction-head outside of the gland-flange, and means for adj usting the follower. Y

S. In a centrifugal pump, the combination with a circular casing and a concentric suction-head extending therefrom, of a gland member within the suction-head comprising an annular follower, and an apertured glandange extending from the face ofthe follower, a rotary runner within the casing provided with a laterally-extending annular throat encircled by the gland-frange and having its end opposed to the face of the follower, and means for introducing fluid under pressure to the packing-chamber defined between the follower and gland-flange to compel said fluid to ow into the casing through the opening defined between the end of the throat and the opposed face of the follower.

l). In a centrifugal pump, the combination with a casing and a concentric suction-head extending laterally from one side thereof, of a gland member within the suction-head comprising a follower and an inclined annular gland-flange extending from the face of the follower at a point intermediate of the edges of the latter and provided with a series of openings, means located upon the exterior of the suction-head for adjusting the follower, a supply-pipe piercing the wall of the suction-head for supplying water under pressure to the interior of said head at the outside of the gland-flange, and a rotary runner within the casing provided with a trunco-conical throat extending into the gland member and having its end edge opposed to the face of the follower.

10. A runner for centrifugal pumps comprising side walls, one of which is provided with a throat, vanes cut away opposite the throat, and removable wear-plates secured to the vanes and having wear-points located opposite the throat and extended beyond the cutaway portions of the vanes.

1l. A runner for centrifugal pumps provided with side walls one of which is provided with a throat, radial Vanes having portions of their edges disposed across the throat and cut away, and detachable wear-plates completely covering the working surfaces of the vanes and provided with thickened wearpoints extended into the cut-away portions of the vanes.

13. A runner for centrifugal pumps comprising side walls and vanes, wear-plates mounted upon the vanes, and lining-plates mounted upon the inner faces of the runnerwalls and having their edges in contact with the wear-plates to assist in the retention of the latter and with the rear face of the next adjacent vane.

14. In a pump, the combination with a casing, and a rotary runner therein provided with a laterally-extending throat, of a gland member encircling the throat and having one wall opposed to the end thereof, and means for supplying fluid under pressure to the packing-chamber defined between the throat and gland member to compel the circulation of said fluid within the chamber, and its passage into the casing around the end of the throat.

15. In a pump, the combination with a casing provided with asuction-head, of a rotary runner within the casing provided with a trunco-conical throat, a gland located within the suction-head, and encircling the throat, and means for supplying fluid under pressure to the interior of the gland.

1G. In a pump, the combination with a casing having a suction-head extended therefrom, of an apertured gland member located within the suction-head and having an annular follower, means for supplying water to the interior of the suction-head outside of the gland member, and means for adjusting the follower.

17. In a centrifugal pump, the combination with a casing and a concentric suction-head extending laterally from one side thereof, of a gland member within the suction-head comprising a follower and an inclined annular gland-flange extending from the face of the follower at a point intermediate of the edges of the latter and provided with a series of openings, means for supplying water under pressure to the interior of said head at the outside of the gland-flange, and a rotary runner within the casing provided with a tru neoconical throat extending into the gland member and having its end edge opposed to the face of the follower.

In testimony that I claim the foregoing as my own have hereto affixed my signature in the presence of two witnesses.

ROBERT W. CHRISTIAN.

Witnesses:

A. F. GRAETER, MALCOLM MoDoNALD.

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